Editing Apple LaserWriter Plus

{{Infobox computer peripheral
| name         = Apple LaserWriter Plus
| image        = [[File:Laserwriter.jpg|250px]]
| caption      = Apple LaserWriter Plus (1986)
| manufacturer = Apple Computer, Inc.
| type         = Laser printer
| release date = March 1986
| discontinued = February 1, 1988
| price        = US$6,798 (1986 retail)
| interface    = LocalTalk (RS-422), RS-232 serial
| compatible   = Macintosh, Apple II, PC (via RS-232)
| dimensions   = 11.5" H × 18.5" W × 16.2" D
| weight       = 77 lbs (35 kg)
| power        = 760W maximum, 115V/60Hz
| model        = M0180
}}

The '''Apple LaserWriter Plus''' was the second model in the LaserWriter series, announced on January 16, 1986 at the Apple World Conference in San Francisco and released in March 1986 at US$6,798. The LaserWriter Plus maintained the same Canon LBP-CX print engine and hardware specifications as the original LaserWriter but doubled the ROM capacity from 512 KB to 1 MB, allowing for 35 built-in PostScript fonts instead of 13. The expanded font library made the LaserWriter Plus the definitive PostScript printer, establishing the 35-font set as an industry standard that remained through PostScript Level 2. Both the LaserWriter and LaserWriter Plus were discontinued on February 1, 1988, replaced by the more compact LaserWriter II series.

== Technical Specifications ==

=== Physical Specifications ===
* '''Dimensions:''' 11.5" H × 18.5" W × 16.2" D (292 × 470 × 411 mm)
* '''Weight:''' 77 lbs (35 kg)
* '''Operating temperature:''' 50°F to 90°F (10°C to 32°C)
* '''Humidity:''' 20% to 80% non-condensing
* '''Acoustic noise:''' 50 dBA operating, 40 dBA standby

=== Performance ===
* '''Print speed:''' 8 pages per minute
* '''Resolution:''' 300 × 300 dpi
* '''First page out:''' Approximately 30 seconds
* '''Engine life:''' 300,000 pages rated
* '''Duty cycle:''' 3,000 pages per month recommended

=== Power Requirements ===
* '''Input voltage:''' 115V AC ±10%
* '''Frequency:''' 60 Hz
* '''Power consumption:''' 760W maximum
* '''Current draw:''' 6.3A maximum
* '''Heat output:''' 2,599.2 BTU per hour

== System Architecture ==

=== Processor and Memory ===
The LaserWriter Plus used identical processing hardware to the original LaserWriter:

'''Central Processing Unit:'''
* '''CPU:''' Motorola MC68000
* '''Clock speed:''' 12 MHz crystal (operating at 11.16 MHz)
* '''Data bus:''' 16-bit
* '''Address bus:''' 24-bit (16 MB addressable)
* '''Wait states:''' 1 wait state on memory access (performance limitation)

'''Memory Configuration:'''
* '''ROM:''' 1 MB mask ROM (doubled from original)
* '''RAM:''' 1.5 MB total DRAM
** 512 KB workspace RAM for PostScript interpreter
** 1 MB frame buffer for page rasterization

* '''RAM type:''' 150ns DRAM chips
* '''Memory expansion:''' None (fixed configuration)

=== Controller Board Design ===
The LaserWriter Plus maintained the streamlined PAL-based architecture:

* '''Logic implementation:''' Monolithic Memories medium-scale integration PALs
* '''Address decoding:''' PAL-based memory management
* '''Timing control:''' PAL-generated signals for DRAM refresh and video timing
* '''Bus interface:''' Direct 68000 bus connection to memory and I/O
* '''ROM addressing:''' Extended addressing for 1 MB ROM space

=== PostScript Interpreter ===
The LaserWriter Plus featured the same PostScript implementation with expanded font resources:

'''PostScript Implementation:'''
* '''Version:''' PostScript Level 1
* '''Licensor:''' Adobe Systems
* '''Language features:''' Complete programming language with stack-based execution
* '''Graphics capabilities:''' Vector graphics, Bézier curves, arbitrary transformations
* '''Font handling:''' Type 1 outline fonts with hinting
* '''Font cache:''' Dynamic allocation in RAM

'''Interpreter Performance:'''
* '''Rasterization:''' Real-time interpretation during printing
* '''Complex pages:''' Could require several minutes for full rasterization
* '''Memory management:''' Dynamic allocation for fonts and graphics

== Print Engine ==

=== Canon LBP-CX Engine ===
The LaserWriter Plus utilized the same Canon LBP-CX laser print engine as the original:

'''Engine Specifications:'''
* '''Technology:''' Laser xerography (electrophotographic)
* '''Photosensitive drum:''' Organic photoconductor (OPC)
* '''Laser type:''' Semiconductor laser diode
* '''Developer system:''' Single-component toner
* '''Fusing:''' Heat roller at approximately 180°C

'''Print Process:'''
# Drum charging to -600V
# Laser exposure creating latent image
# Toner development using magnetic brush
# Transfer to paper via corona wire
# Thermal fusing of toner to paper
# Drum cleaning and discharge

=== Consumables ===
* '''Toner cartridge:''' Apple M0180 or HP 92285A (cross-compatible)
* '''Yield:''' Approximately 3,000 pages at 5% coverage
* '''Drum life:''' Integrated with toner cartridge
* '''Paper tray:''' 250-sheet capacity letter/legal cassette
* '''Manual feed:''' Single-sheet bypass for envelopes/transparencies

== ROM Fonts ==

The LaserWriter Plus included 35 built-in PostScript Type 1 fonts in its 1 MB ROM, establishing what became the standard PostScript font set:

=== Original 13 Fonts (from LaserWriter) ===

'''Times''' (4 styles):
* Times-Roman
* Times-Italic
* Times-Bold
* Times-BoldItalic

'''Helvetica''' (4 styles):
* Helvetica
* Helvetica-Oblique
* Helvetica-Bold
* Helvetica-BoldOblique

'''Courier''' (4 styles):
* Courier
* Courier-Oblique
* Courier-Bold
* Courier-BoldOblique

'''Symbol''' (1 style):
* Symbol (mathematical and Greek characters)

=== Additional 22 Fonts (New in Plus) ===

'''ITC Avant Garde Gothic''' (4 styles):
* AvantGarde-Book
* AvantGarde-BookOblique
* AvantGarde-Demi
* AvantGarde-DemiOblique

'''ITC Bookman''' (4 styles):
* Bookman-Light
* Bookman-LightItalic
* Bookman-Demi
* Bookman-DemiItalic

'''Helvetica Narrow''' (4 styles):
* Helvetica-Narrow
* Helvetica-Narrow-Oblique
* Helvetica-Narrow-Bold
* Helvetica-Narrow-BoldOblique

'''New Century Schoolbook''' (4 styles):
* NewCenturySchlbk-Roman
* NewCenturySchlbk-Italic
* NewCenturySchlbk-Bold
* NewCenturySchlbk-BoldItalic

'''Palatino''' (4 styles):
* Palatino-Roman
* Palatino-Italic
* Palatino-Bold
* Palatino-BoldItalic

'''ITC Zapf Chancery''' (1 style):
* ZapfChancery-MediumItalic

'''ITC Zapf Dingbats''' (1 style):
* ZapfDingbats (ornaments and symbols)

These 35 fonts became the de facto standard for PostScript printers and were included in PostScript Level 2 specifications.

== Interfaces and Connectivity ==

=== LocalTalk Interface ===
Primary connection method using Apple's LocalTalk networking:

'''LocalTalk Specifications:'''
* '''Physical layer:''' RS-422 differential signaling
* '''Data rate:''' 230.4 kbps
* '''Topology:''' Bus with daisy-chaining
* '''Maximum nodes:''' 32 devices (practical limit ~16)
* '''Maximum distance:''' 1000 feet (305 m) total bus length
* '''Connector:''' DB-9 female on printer
* '''Protocol:''' AppleTalk protocol stack

'''LocalTalk Connector Pinout (DB-9):'''
{| class="wikitable" style="width:50%; text-align:center;"
! Pin !! Signal !! Direction
|-
| 1 || Frame Ground || -
|-
| 2 || RxD+ || Input
|-
| 3 || RxD- || Input
|-
| 4 || TxD+ || Output
|-
| 5 || TxD- || Output
|-
| 6-9 || Not connected || -
|}

=== RS-232 Serial Interface ===
Secondary interface for PC compatibility:

'''RS-232 Specifications:'''
* '''Connector:''' DB-25 female
* '''Data rate:''' Up to 19,200 baud (9,600 baud typical)
* '''Data format:''' 8 bits, no parity, 1 stop bit
* '''Flow control:''' XON/XOFF or hardware (RTS/CTS)
* '''Protocol:''' PostScript commands or Diablo 630 emulation

=== Interactive PostScript Mode ===
Accessible via RS-232 for direct printer control:

'''Terminal Connection:'''
* '''Settings:''' 19,200 baud, 8-N-1
* '''Access command:''' Type "executive" to enter interactive mode
* '''Capabilities:''' Direct PostScript programming, diagnostics, font management
* '''Error messages:''' Displayed on terminal for debugging

== LaserWriter to LaserWriter Plus Upgrade ==

Apple offered an upgrade kit to convert original LaserWriter printers to LaserWriter Plus specifications:

=== Upgrade Kit Contents ===
* '''ROM chips:''' Four 256 KB ROM chips to replace original 128 KB chips
* '''Installation manual:''' Detailed service instructions
* '''Font diskettes:''' Screen fonts for Macintosh
* '''Price:''' US$799 (1986)

=== Installation Requirements ===
The upgrade process required:
* Opening the printer case
* Removing the controller board
* Desoldering original ROM chips (if not socketed)
* Installing IC sockets (if required)
* Installing new ROM chips
* Reassembling printer
* Testing with font verification page

=== Upgrade Considerations ===
* Required technical expertise or dealer installation
* Some early LaserWriter units had soldered ROMs requiring socket installation
* Risk of damage to expensive printer if improperly performed
* Warranty implications if user-installed

== Paper Handling ==

=== Input Specifications ===
* '''Standard cassette:''' 250 sheets
* '''Manual feed:''' Single sheets
* '''Paper sizes:''' Letter, Legal, A4, Executive
* '''Paper weight:''' 16-24 lb bond (60-90 g/m²)
* '''Media types:''' Plain paper, transparencies, envelopes

=== Output Specifications ===
* '''Output tray:''' 250-sheet capacity face-down
* '''Stacking:''' Offset stacking not supported
* '''Duplex:''' Manual duplex only

== Diagnostic Features ==

=== Self-Test Page ===
The LaserWriter Plus printed an enhanced self-test page showing:
* Printer serial number
* ROM version (Plus-specific)
* Installed RAM
* Page count
* Complete font samples (all 35 fonts)
* PostScript version
* Print engine status

=== Status Lights ===
Three LED indicators on the front panel:
* '''Ready:''' Solid green when ready to print
* '''Paper:''' Amber when paper low or jam
* '''Service:''' Red for errors requiring service

=== Font Verification ===
Special test page showing all 35 built-in fonts with sample text demonstrating each typeface in various sizes.

== Common Issues and Maintenance ==

=== Preventive Maintenance ===

'''Regular Service Intervals:'''
* '''50,000 pages:''' Clean corona wires, check paper path
* '''100,000 pages:''' Replace transfer corona assembly
* '''200,000 pages:''' Replace fuser assembly
* '''300,000 pages:''' Major overhaul recommended

'''Cleaning Procedures:'''
* '''Toner vacuum:''' Use only toner-rated vacuum
* '''Corona wires:''' Clean with provided brush monthly
* '''Paper path:''' Wipe with lint-free cloth
* '''Exterior:''' Damp cloth with mild detergent

=== Common Failures ===

{| class="wikitable" style="width:90%; text-align:center;"
|+'''Typical Failure Modes'''
! Component !! Symptoms !! MTBF !! Repair
|-
| Fuser assembly || Poor toner adhesion, wrinkled pages || 200K pages || Replace unit
|-
| Corona wires || Light print, streaking || 100K pages || Clean or replace
|-
| Pickup rollers || Paper feed failures || 100K pages || Clean or replace
|-
| DC controller || No power, intermittent operation || 5-7 years || Board-level repair
|-
| Scanner motor || Horizontal lines, distorted print || 300K pages || Replace motor assembly
|-
| ROM chips || Missing fonts, PostScript errors || 10+ years || Replace ROM chips
|}

=== Power Supply Issues ===

The LaserWriter Plus used the same power supply as the original, prone to capacitor failures:

'''Common Symptoms:'''
* Intermittent power
* Failure to maintain ready state
* Random resets during printing
* Voltage regulation problems

'''Capacitor Replacement:'''
* Replace all electrolytic capacitors as preventive maintenance
* Use 105°C rated capacitors for longevity
* Typical service life: 5-7 years

== PostScript Programming ==

=== Font Management ===
The LaserWriter Plus's expanded font set allowed more sophisticated typography:

'''Font Selection Example:'''
```
%!PS
/Palatino-Roman findfont
12 scalefont setfont
72 720 moveto
(LaserWriter Plus with 35 fonts) show
showpage
```

=== Memory Considerations ===
* '''VM (Virtual Memory):''' 512 KB available (same as original)
* '''Font cache:''' Shared among 35 fonts (vs. 13 in original)
* '''Performance impact:''' Slightly slower font switching with larger ROM
* '''Downloaded fonts:''' Less RAM available due to larger font cache requirements

=== Font Substitution ===
The LaserWriter Plus established standard font substitutions:
* Times → Times-Roman
* Helvetica → Helvetica (already included)
* Courier → Courier (already included)
* These mappings became industry standards

== Service Information ==

=== Service Mode Access ===
Internal DIP switches provided service functions:
* '''SW1:''' Continuous self-test with all fonts
* '''SW2:''' Suppress startup page
* '''SW3:''' Diablo 630 emulation mode
* '''SW4:''' Reserved

=== Test Points ===
The DC controller board included test points for:
* +5V DC logic supply
* +24V DC motor supply
* -24V DC bias supply
* High voltage (measure with appropriate probe)

=== Adjustment Procedures ===
* '''Print density:''' Potentiometer on DC controller
* '''Registration:''' Mechanical adjustment of laser unit
* '''Fuser temperature:''' Thermistor calibration

== Compatibility ==

=== Operating System Support ===
* '''System 2.0 or later:''' Full LaserWriter Plus support with new fonts
* '''System 6.x:''' Optimal performance
* '''System 7.x:''' Supported through 7.5.5
* '''Apple II:''' Via AppleWorks with font selection
* '''MS-DOS:''' PostScript drivers with full font access
* '''UNIX:''' lpr with PostScript support

=== Application Support ===
Applications with LaserWriter Plus font support:
* Aldus PageMaker 1.2 and later (font menu expansion)
* MacWrite 4.5 and later
* MacDraw 1.9 and later
* Microsoft Word 1.05 for Macintosh
* Adobe Illustrator 88
* Ready,Set,Go! 3.0
* QuarkXPress 1.0

== Service Manual ==
<pdf width="800" height="500">File:Apple LaserWriter Printers Volume I.pdf</pdf>

The complete Apple LaserWriter Plus service manual is available on the [[:Category:Apple Service Source|Apple Service Source]] page.

== Comparison with Original LaserWriter ==

{| class="wikitable" style="width:90%; text-align:center;"
|+'''LaserWriter vs. LaserWriter Plus'''
! Feature !! LaserWriter (1985) !! LaserWriter Plus (1986)
|-
| ROM size || 512 KB || 1 MB
|-
| Built-in fonts || 13 || 35
|-
| Launch price || US$6,995 || US$6,798
|-
| Weight || 77 lbs || 77 lbs
|-
| Print engine || Canon LBP-CX || Canon LBP-CX
|-
| Processor || 68000 @ 11.16 MHz || 68000 @ 11.16 MHz
|-
| RAM || 1.5 MB || 1.5 MB
|-
| Resolution || 300 dpi || 300 dpi
|-
| Speed || 8 ppm || 8 ppm
|}

== Related Pages ==
* [[LaserWriter|Apple LaserWriter]]
* [[Apple Desktop Bus]]
* [[LocalTalk]]

{{Navbox-AppleVintageAccessories}}

[[Category:Apple Vintage Accessories]]